TOKYO (AFP) - The approval rating for the cabinet of Japanese Prime Minister Taro Aso plunged to 25.5 percent, a poll showed Sunday, revealing for the first time that more people support his political rival. The Aso government's support rate fell by 15.4 percentage points from last month, the survey carried out by Kyodo News showed, as ruling party lawmakers have criticised Aso for failing to do more to protect the Japanese economy. The disapproval rating for Aso's cabinet rose to 61.3 percent, up 19.1 points from November, said Kyodo, which carried out the telephone survey on Saturday and Sunday, querying more than 1,000 respondents. According to the poll, 34.5 percent of respondents said Ichiro Ozawa, leader of the opposition Democratic Party of Japan, was better fit to serve as the prime minister, while 33.5 percent said Aso was more suited for the job. It was the first time Ozawa received more public support than Aso, Kyodo said. Nearly 58 percent of the poll participants said Aso should not delay the introduction of additional economic measures until next month, while 26 percent approved of his decision. Support for Aso and his government has taken a nosedive in recent weeks due to fears over his ability to manage Japan's economy amid the global financial crisis. Within his own Liberal Democratic Party, criticism is escalating. Former government minister Yoshimi Watanabe said he might leave the ruling party if Aso fails to offer new measures and to call snap elections soon. "I will do my part if decisions are made" to act against the Aso cabinet, Watanabe said on a TV Asahi talk show. "If calls grow that I should (leave the party), I will consider it as a possibility," said Watanabe, son of a late LDP heavyweight. "In order to break the current political deadlock, the only solution is to call general elections," he said.